1. Field of the Invention
The present invention relates to liquid detergent compositions, and more particularly, to liquid detergent compositions which are suited for cleansing the skin, hair and the like and which provide excellent feel in use, have excellent foaming ability and are stable for a long term storage.
2. Discussion of the Background
Recently, liquid detergent compositions such as liquid body shampoos have widely been used in place of soap because of their easy handling and good feel in use.
Meanwhile, surfactants of the phosphoric ester type, which are anionic surfactants, are known to be very mild to the skin and the hair, and are utilized as a component of detergent compositions.
When such phosphate surfactants are converted into alkanolamine salts, the resulting Kraft point is low, which results in advantages in the liquidizing process. However, the foaming-forming ability of such alkanolamine salts is poor. On the other hand, when they are converted into an alkali metal salt, it provides rich foams, but the Kraft point is high, which results in a disadvantage in the liquefying process.
Separately, Japanese patent publication Kokai No. 17343/1993 discloses a mixture of phosphate surfactants represented by formulae (1) and (2) shown below as providing rich foams and possessing a low Kraft point.
When these phosphate surfactants are incorporated into a detergent composition, better foam producing ability is obtained than obtainable in the single use of alkanolamine salt, but the property of foam is poor and rough, and besides, foam producing ability is still inferior when compared to other commonly used surfactants in this technical field.
Thus, there remains a need for detergent compositions which have excellent foaming ability and are mild to the skin and are easily prepared.